1. Field of the Invention
The present invention relates to an apparatus for pushing a plurality of hollow cylindrical members into predetermined positions, respectively.
2. Description of the Related Art
As well known in the art, cylinder blocks manufactured in the automotive industry are a component of an internal combustion engine used as a propulsive source for automobiles. In many cases, cylinder sleeves are inserted in respective bores defined in the cylinder block. When the internal combustion engine is in operation, pistons which move back and forth in the respective cylinder bores have their outer side wall surfaces held in sliding contact with the inner wall surfaces of the cylinder sleeves.
The cylinder sleeves are inserted in the respective bores by insert casting. Specifically, after the cylinder sleeves are placed in given positions within a casting mold, a molten metal is poured into the casting mold around the cylinder sleeves, and then cooled into a solid cylinder block with the cylinder sleeves enveloped therein.
One known apparatus for inserting cylinder sleeves into given positions within a casting mold is disclosed in Japanese Laid-Open Patent Publication No. 2000-197954. The disclosed inserting apparatus has a first inserting mechanism for inserting cylinder sleeves into respective portions in a V-type internal combustion engine in which at least two bores are arranged in a V-shaped configuration, and a second inserting mechanism for inserting cylinder sleeves into respective portions in a straight internal combustion engine in which all the bores are aligned inline. The first inserting mechanism has a lower inserting unit and an upper inserting unit. For example, for a six-cylinder V-type internal combustion engine in which two sets of three bores are arranged in parallel, three cylinder sleeves are inserted into one array of three cylinders with the lower inserting unit, and other three cylinder sleeves are inserted into another array of three cylinders with the upper inserting unit.
In an inserting apparatus constituted as the one disclosed in Japanese Laid-Open Patent Publication No. 2000-197954, if the number of engine cylinders involved increases, then the number of cylinder sleeves to be held by the lower inserting mechanism or the upper inserting mechanism needs to be increased. As a result, the disclosed inserting apparatus becomes more complex in structure and greater in weight. The process of servicing the inserting apparatus for maintenance also becomes tedious and time-consuming.
In addition, the inserting apparatus includes a sleeve supply station having two different sleeve supply mechanisms for supplying cylinder sleeves to the first inserting mechanism and the second inserting mechanism. The two different sleeve supply mechanisms tend to make the inserting apparatus complex in structure.